简介:BrookiteTiO2,thelatestTiO2photocatalyst,promisestobeaninterestingcandidateforphotocatalyticapplicationsbecauseofitsuniquephysicalandchemicalproperties.Inthisstudy,pure-phasebrookiteTiO2withaquasi-sphericalnanostructurewassuccessfullysynthesizedviaasolvothermalmethodusingtetrabutyltitanate(Ti(OC4H9)4,TBOT)astheTisourceinthepresenceofoxalicacid.NaOHwasusedtoregulatethepHofsolution.Thestructureandmorphologyofthesampleswerethenanalyzedusingmultiplemethods,suchasX-raydiffraction(XRD),Ramanspectroscopy,scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM),Brunauer–Emmett–Teller(BET)measurementsandultraviolet–visiblediffusespectroscopy(UV–Vis).Photocatalyticactivitiesoftheas-synthesizedbrookiteTiO2wereevaluatedbydegradingaqueousmethylenebluesolutionunderUVlightirradiation.Theeffectofthermaltreatmenttemperatureonphotocatalyticactivityofthesampleswasalsoinvestigated.TheproducedbrookiteTiO2nanopowderscalcinedat500°Cfor2hshowedthehighestphotocatalyticactivity,andthecorrespondingdegradationrateofmethyleneblue(10mg/L)reached96.7%after90minofillumination.Inaddition,theformationmechanismofpure-phasebrookiteTiO2wasinvestigated.Itwasfoundthattheformationofpure-phasebrookiteTiO2inthisstudywasascribedtothecombinedactionofoxalicacidandsodiumhydroxide.
简介:水生植物对富营养化水体有净化作用.通过凤眼莲和水芹的水培实验,研究水生植物对富营养化程度不同的水体中不同形态氮、总磷、总有机碳的影响.结果表明,培养28d后,2种水生植物都表现出较好的去除总氮和氨氮的效果,在富营养化严重的生活污水中,凤眼莲和水芹对总氮去除率分别为87.3%和77.8%,凤眼莲作用优于水芹,氨氮的去除率分别为95.7%、96.3%,作用相当.硝酸盐氮在培养周期内总体呈现出上升的变化趋势,亚硝酸盐氮的变化规律不明显.凤眼莲和水芹对富营养化严重的生活污水中总磷的去除率分别达到93.7%和53.4%,效果显著,凤眼莲作用优于水芹.凤眼莲和水芹对2种水体中总有机碳的去除率在52.4~65.8(%)之间,水芹的去除效果略高于凤眼莲.
简介:Thepreparationofcalciumphosphate(CP)coatingonaluminaceramicsusingelectricpulsestimulatingmethodhasbeeninvestigated.Thecup-shapedaluminaceramicsweresoakedinasimulatedbodyfluid(SBF),andasquarepulsepotentialwithfrequencyof1Hzandvoltageof110Vwasappliedbetweentheinnerandoutersurfacesofthealuminacup.SurfacemorphologyofCPcoatingsduringdifferentdepositionperiodswasobservedbyaPhilipsXL-30scanningelectronmicroscope(SEM).CompositionalanalysiswasexaminedbyEDAX.ThemechanismofnucleationandgrowthofCPcoatingwasdiscussed.SEMresultindicatesthatthecoatingcomprisesofalargenumberoftinyneedle-likegrainsandhasaporousmicrostructure.ThereisastrongbondbetweenthedepositedlayerandAl2O3substrate,whichmaybeduetothegentlegrowthofthebiomimeticmethod.TheEDAXanalysisindicatesthatmaincompositionofthecoatingiscalciumandphosphor.TheformationofCPcoatingmaybecontributedtothestimulationofelectricpulseandthehighionsconcentrationwhichis1.5timesoftheconcentrationofSBFsolution(1.5SBFsolution).SuchsurfacefunctionalizationmethodbyelectricpulsepotentialcanbeusedtoprepareCPcoatingonvariouselectric-insulatingbioinertmaterialsforimprovingtheirbioactivecharacter.
简介:基于对域外P2P行业监管的梳理和分析,结合我国P2P小额信贷中介服务机构所兼具的创新性金融服务机构、投资咨询类中介服务机构和电子商务金融创新服务平台的三重性质,我国应当尽快完善并不断发展P2P小额信贷中介服务行业的法律制度体系建设,践行多方推动、统筹兼顾、虚实结合、着力创新、注重实效、规范发展、保障安全的新型监管理念并将政府主导型监管制度和市场需求引致型监管制度演变相结合,从而建立起由中国人民银行主导监管、银监会在相应业务领域紧密配合、地方政府严格实施、工商行政管理机关和工信部门积极参与的P2P行业监管框架.